Leishmaniasis is caused by flagellated protozoan parasites of the genus Leishmania, which are obligate intracellular parasites of phagocytic macrophages. Leishmaniasis has been designated as one of six major tropical diseases by the World Health Organization (WHO). Leishmaniasis is vector-borne disease by the bite of blood-sucking female sandfly vectors, resulting in the parasite inoculation to the skin, viscera or the like of mammalian hosts. The symptoms of Leishmaniasis is fatal in severe ranging from mild to heal, but pentavalent antimony formulations have been used primarily as a treatment known to cause severe adverse side effects. Therefore, there is a demand for a new drug having a low risk of adverse side effects. And Amphotericin B was used originally as an antifungal agent, which is also used to treat leishmaniasis. Furthermore, AmBisome has been developed as a drug suppressing the adverse side effects, but this drug has a problem that the drug is expensive.
On the other hand, it has been reported that marine algae-derived metabolites exhibit an anti-leishmanial activity (see, for example, Non-Patent Document 1). However, this document does not specify which compound derived from marine algae would have an anti-leishmanial activity.